1. Field of the Invention
The invention relates generally to a power save system in a network and, more particularly to a periodic power save system in an ad-hoc wireless network.
2. Related Art
A wireless network (e.g., Wi-Fi based on IEEE 802.11 standards) may be characterized as an infrastructure mode network or an ad-hoc mode network depending on whether the stations within the wireless network can directly communicate with other stations in the network. FIG. 1(A) illustrates an example of an infrastructure mode wireless network, which may typically comprise an access point 2 and stations 4, 6 and 8. In the infrastructure mode network, the stations 4, 6 and 8 are not configured to directly communicate with each other, and any communication between the stations 4, 6 and 8 must be channeled through the access point 2.
In contrast, an ad-hoc mode network allows each station to communicate directly with each other, as illustrated in FIG. 1(B). Thus, in the ad-hoc mode wireless network, there is no central access point controlling communication among the stations 4, 6 and 8. Ad-hoc devices are configured to communicate only with other ad-hoc devices, and they are not able to communicate with any infrastructure devices or any other devices connected to a wired network.
Considering that a significant portion of the Wi-Fi devices are portable devices (e.g., cellular phones, portable gaming devices, wireless headsets, wireless headphones, wireless speakers and the like), power consumption has become an important issue for the Wi-Fi devices. This has led the IEEE to standardize the infrastructure mode network power save protocol. However, due to the decentralized nature of ad-hoc mode networks, it is much more difficult and complicated to implement power save algorithms when there is no central access point that dictates all the decisions related to power consumption in the network.